Renewable fuse



Jan, 13, 1931. F, c, LA A 1,788,769

RENEWABLE FUSE F iled March 23, 1928 INVENTOR Patented Jan. 13,1931

UNITED STATES,

PATENT-5,OFFICE FRANK 0. .LA MAR, or NEW YOBK,,1\T. Y., ASSIGNOR TO.GREAT WESTERN FUSE COM- rANYmF PITTSBURGH, PENNSYLVANIA, A CORPORATIONon DELAWARE V RENEWABLE Fuss Applicationfiled March 23,1928. Serialmania.

The purpose which I have in view is the provisionof a novel renewablefuse structure which is of simple construction, 'yet I 'cated' at 6,hasfiXe-dly mounted thereon the circular metal closure head 8 which,when the'parts are in place, closes the outer end of'the correspondingferrule 2.

rugged and durable; which may bereadily assembled, disassembled andrenewed by unskilled persons; which is efiicient in operation, and whichhas its ends efficientlysealed v against the outward travel of flames.along the terminal blades. w In the accompanying'drawings, wherein Ihave illustrated the best embodiment of the principles of my inventionnow known to me, Fig. 1 is a longitudinal section ofthe fuse taken online l1in Fig. 3. I Fig. 2 is a broken elevation of the left end of thefuse shown in Fig. 1, the fuse being turned on its longitudinal axisninety degrees from its .position in Fig.1 and the screw cap being shownin diametric sectionv Fig. 3 is an end view of the fuse looking from theleft in FigsJl and 2.

Fig. 4 is an elevation showing the terminal blades and the fusible linkassembled together. 3

Fig. 5 is an inner end view of the left hand terminal blade in Figs. 1and 4.

Fig. 6 is an inner face view of the slotted anchoring washer.

, Fig. 7 is an end View of one of the two ferrules which are preferablyidentical in structure. g

Fig.8 is an inner end viewof the right hand terminal blade in'Figs. 1and 4. 7

Referring to the drawings, 1 indicates the tubular shell of insulatingmaterial,

such as fibre. V I

At each end said shell has mounted thereona metal ferrule 2, the samebeing held fixedly to the shell as by threadedengagement'and riveting.

The outer ends of said ferrules 2 are recessed at two opposite points toform the seats 3. i

The outer ends of the ferrules are ex teriorly threaded to receive theannular metal screw caps 4.

The shell land the ferrules '2'form the tubular body of the fuse.

5 and 6 indicate the two metal terminal blades to the inner'ends ofwhich are detachably connected the ends of the fusible link'7L V One ofthe terminal blades, the one indi- Said head is provided on its innerface ends engage the seats 3 in the end of the ferrule 2 and thusprevent the head and terminal blade from rotating relative to the fusebody.

Outside, of the closure head 8 the sides'of the blade 6 are notched asat 10 to provide a somewhatreduced neck in the blade.

The screw cap 4, two of which are used,

' one on each end of the fuse body is provided with an annular inwardlyextending flange '11 at its outer end which, when the cap is screweddown snugly in place,clamps the closure-head 8 rigidly, on the end ofthe fuse body.

By providing the flange of the screw cap with opposed notches 12, thescrew cap when turned int othe proper position may be slipped down overthe blade 6' until its flange fl'conies opposite the notches 10 of theblade,

thus rendering the cap rotatablerelative to the blade for tightening onthe fuse body.

By notching the terminal blade and the flange of the screw cap I amenabled to employ a wider clamping flange 11 and thus obtaina bettercompression on the closure head 8.

The disk 13 is so positioned on the terminal blade 5 that when the partsare in position,'the anchoring washer 14 may be slipped between the diskand the corresponding end of the fuse body. The anchoring washer iscircular and of such diameter that it closes the end of the'fuse bodywhen in place against the end of the corresponding ferrule.

The washer 14 is provided with a diametrically disposed slot 15 open atone end to provide clearance for the terminal blade 5 as the washer 14is slid laterally into position.

The washer 14 is provided with a transversely disposed rib 16 on itsinner face whose ends engage the seats 3 in theferrule 2 when the washeris in position.

Outside of the disk 13-the terminal blade 5 is notched at its oppositeedgesas -at-17, thus providing a somewhat restricted neck in the bladebetween the notches. i

The corresponding screw cap {1, with its notches 12- registering withthe edges of the terminal blade 5, is now slipped down over the latteruntil its flange 11 is opposite the notches 17. The cap is thenscrewed-snugly down on the end of the fuse body, clamping the disk 13snugly down on the washer l4-and thus sealing the edges of the slot 15against the escape of flames outwardly along the blade. clamped tightlyonto the'end of the fuse body.

' To assemble the fuse, the terminal blades are first attached to theends of the fusible link and the terminal blade 5 is inserted intotherightend of the fuse body in Fig. l and pushed through the same untilthe closure head 8 rests against the end of the fuse body with its ribs9 engaging the ferrule seats 3.

The corresponding cap 4 is then slid down over the terminal blade 6 andscrewed snugly in place. I

The anchoring washer is then slid into place between the disk 13 and theend of the fuse body with its rib 16 engaging the ferrule seats 3.

The corresponding cap 4 is then slid down over the terminal blade 5 andthen screwed snugly in place.

To disassemble the fuse, the last mentioned cap 4 is first unscrewed andits notches 12 brought into registration with the edges of the terminalblade 5 and then lifted off the latter. i

The anchoring washer 14 is slid from between the end of the fuse bodyand the disk 13.

The other cap 4 is then removed from the other end of the fuse body, andthe parts are thus released.

It is evident from the foregoing that my improved fuse has its endsefficiently sealed against the outward travel of the flames along tlieblades.

It is simple and inexpensive of construction, containing a minimumnumber of parts. Furthermore it may be quickly and readily assembled,disassembled and renewed. 'i

lVha-t I desire to claim is 1. Ina renewable fuse,the combination of awere s b dy a ermin l b d a The washer 14 is thus also ranged toextendthrough the end of said body, a disk fixedly mounted on said terminalblade and passable with said terminal blade through the fuse body, ananchoring washer having a dian'ietrically disposed slot to provideclearance for the terminal blade arranged to'be slid laterally in placebetween the end of the fuse body and the disk, said washer and fuse bodyhaving interengaging portions to prevent rotary motion of the washerrelative to the fuse body, and a cap screwed on the end of the fusebody, said'cap having an inwardly extending annular flange which fitsdown in flat surface contact against the outer face of the disk, thusclamping the disk snugly against the washer and'the washer snuglyagainst the end of the fuse, the bearing on the cap on the fixed washerbeing in a line parallel with the axis of the fuse.

2. In a renewable fuse, the combination of a tubular fuse body, aterminal blade arranged to extend through the end of said body, a diskfixedly mounted on said terminal blade and passable with said terminalblade through the fuse body, an anchoring washer having a diametricallydisposed slotto provide clearance for the terminal blade arranged to beslid laterally in place between the end of the fuse body and the disk,said washer and fuse body having intcrengaging portions to preventrotary motion of the washer reative to the fuse body, anda cap screwedon the end of the fuse body, said cap having an inwardly extendingannular flange, the bore of said flange being of too small diameter tonormally pass down over the blade but said flange being notched out atopposite points so that when turned into proper position the cap may beslipped down over the blade and the blade having a neck portion ofreduced width adjacent to the disk to clear the flange of the cap andpermit the cap to be screwed up on the end of the fuse body, therebyclamping the disk snugly against the washer and also clamping the washersnugly against the fuse body, the bearing of the cap on the fixed washerbeing in a line parallel with the axis of the fuse.

Signed at New York, N. Y. this 19th day of March, 1928'.

' I! FRANK C. LA MAR.

